Thermal and Thermomechanical Performance of Energy Piles with Double U-Loop and Spiral Loop Heat Exchangers

Luo J, Zhang Q, Zhao H, Gui S, Xiang W, Rohn J, Soga K (2019)

Publication Type: Journal article

Publication year: 2019

Journal

Journal of Geotechnical and Geoenvironmental Engineering American Society of Civil Engineers

Book Volume: 145

Article Number: 04019109

Journal Issue: 12

DOI: 10.1061/(ASCE)GT.1943-5606.0002175

Abstract

This study investigates the thermal and thermomechanical behavior of two energy piles with either double U-loop or spiral loop heat exchanger configurations. The piles were installed in a sandstone formation, and a heating-recovery-cooling-recovery cycle was applied to the piles. In both piles, the shaft resistance evaluated from the measured axial-strain distributions was greater in the heating mode than that in the cooling mode. In the heating model, radial expansion was detected. The radial stress at the pile-soil interface increased due to the high stiffness of the sandstone, which in turn increased the shaft friction. In the cooling stage, the radial contraction of the pile was measured, which in turn decreased the radial stress at the pile-soil interface. The amount of pile contraction was similar to the thermally induced free contraction, and consequently large pile settlement was measured at the top of the pile during cooling. The normalized heat-transfer rate shows similar thermal efficiency between heating and cooling, indicating the heat transfer was not much affected by the radial expansion and contract of the piles.

Authors with CRIS profile

Joachim Rohn Professur für Angewandte Geologie und Modellierung von Umweltsystemen

Involved external institutions

China University of Geosciences / 中国地质大学 CN China (CN) China Three Gorges Corporation CN China (CN) Changjiang Institute of Survey, Planning, Design and Research (CISPDR) CN China (CN) University of California, Berkeley US United States (USA) (US)

How to cite

APA:

Luo, J., Zhang, Q., Zhao, H., Gui, S., Xiang, W., Rohn, J., & Soga, K. (2019). Thermal and Thermomechanical Performance of Energy Piles with Double U-Loop and Spiral Loop Heat Exchangers. Journal of Geotechnical and Geoenvironmental Engineering, 145(12). https://dx.doi.org/10.1061/(ASCE)GT.1943-5606.0002175

MLA:

Luo, Jin, et al. "Thermal and Thermomechanical Performance of Energy Piles with Double U-Loop and Spiral Loop Heat Exchangers." Journal of Geotechnical and Geoenvironmental Engineering 145.12 (2019).

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